过表达Wnt3基因抑制肝前体细胞凋亡

目的利用腺病毒载体转染体外培养的肝前体细胞，研究过表达Wnt3对肝前体细胞凋亡的影响。方法用携带Wnt3的腺
病毒载体（Ad-Wnt3）转染肝前体细胞，同时设立空载体腺病毒转染组（Ad-GFP）为对照。转染72 h 后，用荧光显微镜观察
Hoechst33342 染色后细胞凋亡情况；流式细胞术检测Annexin-PE/7-ADD法标记的细胞凋亡率；RT-PCR和Western blot分别检
测细胞凋亡相关蛋白Bax、Bcl-2和Bcl-xl的mRNA及蛋白表达水平。结果qRT-PCR和Western blot结果显示，Wnt3在肝前体
细胞中特异性表达，表明腺病毒系统Ad-Wnt3能高效转染肝前体细胞。与对照组相比较，肝前体细胞转染Wnt3后，肝前体细胞的
凋亡水平明显下降，凋亡相关蛋白Bcl-2和Bcl-xl的mRNA及蛋白表达水平明显升高（P<0.05）。Bax的mRNA及蛋白表达水平
则明显下降（P<0.05）。结论在肝前体细胞中，Wnt3基因过表达能抑制肝前体细胞凋亡，其机制可能是通过Bcl-2家族起作用。

Overexpression of Wnt3 inhibits apoptosis of hepatic progenitor cells in vitro

Objective To investigate the effects of adenoviral vector-mediated over-expression of Wnt3 on the apoptosis of
hepatic progenitor cells in vitro. Methods Hepatic progenitor cells transfected with Ad-GFP-Wnt3 vector or the control vector
Ad-GFP were examined for cell apoptosis under fluorescence microscopy with Hoechst 33342 staining, and the proportion of
apoptotic cells were determined by flow cytometric analysis with Annexin-PE/7-ADD staining. The mRNA and protein
expressions of Bax, Bcl-2 and Bcl-xl in the cells were detected by real-time PCR and Western blotting, respectively. Results
Real-time PCR and Western blotting showed a high expression of Wnt3 in Ad-GFP-Wnt3-transfected hepatic progenitor cells,
which exhibited significantly decreased cell apoptosis as compared with the control group. The expressions of Bcl-2 and Bcl-xl
mRNA and proteins increased significantly while Bax expression decreased obviously in Ad-GFP-Wnt3-transfected cells (P<
0.05). Conclusion Adenoviral vector-mediated over-expression of Wnt3 can suppress apoptosis of hepatic progenitor cells
possibly through the Bcl-2 pathway．